Caption: Vitamin B. Polarised light micrograph of crystals of para-aminobenzoic acid (PABA), a component of folic acid which is one of the B complex vitamins. This acid was formerly regarded as a vitamin belonging to the group known as the vitamin B complex. PABA is a growth factor for some bacteria and in certain animals is needed for the synthesis of proteins and red blood cells. It is used in pharmaceutical preparations such as creams and lotions as a sunscreen agent to prevent sunburn. Magnification: x8 at 35mm size.